Table of Contents

TYPE OF ERRORS IN PHP

There are basically four type of errors in php .

It is simple message to end-user .

it does not stop execution of script.

If we are trying to access undefined variable , output is notice message.

Example:

 <?php

 Error_reporting(E_all)  // reports all errors.

Echo $k;

Echo “hello”;

?>

Output: notice error

Hello

By default , we con not see notice message on browser to display notice message, we should use error_reporting(E_ALL)function.

It is same as notice, does not stop execution of script. If we are trying to access undefined constants, output is warning message.

Constant is same as variable, but constant value con not be changed.

In php, using function, we can declare constants.

Using constant function , we can access constants.

Example:-

<?php

Define(“city”, “AAA”);

Echo constant(“city”);

Echo constant(“stt”); // warning

Echo ”hello”;

?>

Output :

AAA

Warning

Hello

Fatal error stops the execution of script from the line when error is occurred .

If we try to access undefined functions. Output is fatal error.

Example :-

<?php

 Echo “codelack”

Defin(“city”,”AAA”);   // fatal error

Echo “hello”;

?>

If there is syntax mistake in the script, output is parse error.

Parse error stops execution of complete.

Example :-

<?php

Echo ”first line “;

Echo  “2nd line”     //syntax error

Echo  “3rd line” ;

?>

Output : parse error (stops full script)

<?php

Echo” first line “;

Echo “2nd line”;

Echo  “3rd line “   // executes since last line its no need of ;

?>

Output : first line 2^nd line 3^rd line

Using this function, we check whether the function is set with any value or not

Example:-

<?php

$x=100;

Echo isset($x);

?>

Output: 1(true)

Using this function, we can delete the value of variable .

<?php

$x=100;

Unset($x);

Echo isset($x);

?>

Output : false (nothing displays)